JPH0316026B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic brush developing machine for an electronic copying machine.

[Conventional technology]

Generally, in electrophotography, a developing machine as shown in FIG. 3 is used, and the developer 8 is conveyed from the lower side to the upper developing roll 2 to form a magnetic brush, and the surface of the photoreceptor 3 is coated with this magnetic brush. The electrostatic latent image on the photoreceptor is developed by sliding contact. In this type of device, when the toner concentration decreases, toner is dropped into the developing machine by a dispense roll 14 from a toner cartridge cartridge 13 provided above the developing machine and replenished, but the toner density is kept uniform in the axial direction. In order to achieve this, it is necessary to form the toner cartridge 13 to have a size approximately equal to the entire length of the developing roll 2. Therefore, the mounting position of the toner cartridge 13 is limited to the upper part of the developing machine.
In addition, the toner is placed on the dispense roll 14 in the developing machine.
A blender 15, a paddle wheel 16, etc. are provided so that after passing through, the developer is quickly and uniformly mixed into the developer. For this reason, developing machines have become larger,
Furthermore, there was a problem in that the cost increased because an expensive paddle wheel was required.

In the device described in JP-A-58-163968, the developer is transferred between the upper auger and the lower auger only through the drop hole 14 drilled at the bottom of the guide 13, and the developer is transferred from the lower auger to the upper auger. Since it does not have a second supply port for supplying developer, only one developer stirring path is formed, resulting in poor stirring efficiency. Also, although the device described in Utility Model Application Publication No. 55-108445 is arranged horizontally, the agitation of the developer is
The agitation efficiency is not good because the stirring is carried out only by the two holes at both ends of the partition plate shown in the figure.

[Problem that the invention seeks to solve]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a developing machine in which the toner is well mixed with the developer when the toner is replenished, and which can be manufactured in a small size at low cost.

[Means and actions for solving problems]

According to the present invention, the above problem can be solved by: a developing roll provided facing the electrostatic latent image carrier; a developing housing containing the developing roll; The electrostatic latent image carrier includes an upper auger provided vertically on a side opposite to the side facing the electrostatic latent image carrier, a lower auger, and a partition member provided in a region between the upper auger and the lower auger. , the partition member includes a developer receiving portion that receives the developer removed from the developing roll, and a rear chute portion that drops the removed developer from behind the upper auger toward the lower auger by rotation of the upper auger. a first supply port for supplying the developer conveyed by the upper auger to the lower auger near one end in the longitudinal direction of the partition member; and a developer conveyed by the lower auger. The problem is solved by an electronic copying developing machine characterized in that a second supply port for supplying the agent to the upper auger near the other end in the longitudinal direction of the partition member is provided.

The auger has a function of transporting the developer, and the upper auger and the lower auger transport the developer in opposite directions. The gap around the partition wall is a passage for the developer to fall from the partition wall, and a passage for the developer to be pushed up from the bottom of the casing.
The developer that has been moved on the partition wall by the upper auger falls from one end of the partition wall to the bottom of the casing, is moved in the opposite direction on the bottom part by the lower auger, is pushed upward through the gap at the other end of the partition wall, and moves on the partition wall again.
Further, the developer on the partition wall also falls from the shutter, and the developer at the bottom of the casing also moves toward the developing roll. Since the developer circulates within the developing machine by repeating such movements, the developer is sufficiently agitated, a portion of the developer is constantly attached to the developing roll, and toner is uniformly supplied to the developing roll.

In the developing machine of the present invention, the developer is stirred through the path of the developing roll of the partition member → the developer receiving part → the upper auger → the rear chute → the lower auger → the developing roll, which is not disclosed in Utility Model Application Publication No. 55-108445. a first developer stirring path which is not disclosed in JP-A-58-163968, and a second developer stirring path in which the developer is stirred through the path of the lower auger → the second supply port at the end → the upper auger. Therefore, an extremely higher stirring efficiency than these known developing machines can be obtained.

〔Example〕

An embodiment of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a sectional view of the developing machine of this embodiment, and FIG. 2 is a sectional view taken along the line aa in FIG. A developing roll 2 is provided in the casing 1 in close proximity to the photoreceptor 3, and behind it, that is, in the opposite direction from the photoreceptor 3, two upper and lower augers 4, 5 are provided.
These rotate in opposite directions. In FIG. 1, the upper auger 4 rotates counterclockwise, and the lower auger 5 rotates clockwise. A partition wall 6 is provided between the upper auger 4 and the lower auger 5, and this partition wall 6 is connected to the developing roll 2.
It is provided with a receiver 9 for receiving developer 8 regulated from above by a trimmer 7 and a shutter 10 for guiding the developer 8 to fall to the bottom of the casing. A gap 12 is provided between the shooter 10 and the casing 1. As is clear from FIG. 2, the upper auger 4 and the lower auger 5 each have a spiral portion 11 inclined in the same direction, and when rotated in the direction shown by the arrow in FIG. The lower auger 5 transports the developer 8 on the casing 6 to the right, and the lower auger 5 transports the developer 8 at the bottom of the casing to the left. On the other hand, there is a gap 12 between the end of the partition wall 6 and both side surfaces 1a of the casing.
The developer 8 moving on the partition wall 6 falls to the bottom of the casing through the gap 12 at one end thereof, and the developer 8 moving on the bottom of the casing is pushed up onto the partition wall 6 through the gap 12 at the other end of the partition wall 6. In this way, the developer 8 inside the casing 1 moves in the direction of the arrow B→C→D→
It circulates like E.

Furthermore, since the augers 4 and 5 also transport the developer 8 in the peripheral direction while rotating, the developer 8 on the partition wall 6 is transported onto the shutter 10 by the upper auger 4 and in the direction of arrow A in FIG. It falls on the shooter 10. Similarly, the developer 8 at the bottom of the casing is conveyed to the developing roll 2 by the lower auger 5.

The developer that is stirred in this way does not move in a plane but in a curved manner, so when toner is replenished, the toner is evenly distributed in the developer, and the concentration in the axial direction is also uniform. become. Therefore, the toner is well mixed with the developer no matter where you replenish the toner, so the toner cartridge for replenishing the toner can be installed in any position, and the toner cartridge can be installed evenly in the axial direction. There is no need to replenish toner, and toner can be replenished at any position (for example, the position indicated by arrow G).

Effects of the Invention According to the present invention, since the developer is stirred extremely well, there are no restrictions on the shape or mounting position of the toner cartridge for replenishing toner, and toner can be replenished from any position. . The developer removed from the developing roll is transferred to the developing roll of the partition member → developer receiving section → upper auger → rear chute →
Lower auger → first developer stirring path that is stirred with the developing roll, developer receiving part of partition member → first supply port at the end of the upper auger → lower auger → second supply port at the end →
Since the upper auger and the second developer stirring path are formed, the developer stirring efficiency is doubled compared to the conventional double auger type, and the mixing of old developer and new developer is improved. As efficiency increases,
The probability of mutual frictional electrification between toner carriers increases, and the triboelectricity imparted to the toner becomes better. Furthermore, since the developer can be well stirred and supplied to the developing roll without the need for a blender or paddle wheel as in the past, the developing machine can be made smaller and the manufacturing cost can be reduced.

[Brief explanation of the drawing]

1 and 2 are sectional views of the developing machine of the present invention, and FIG. 3 is a schematic diagram of a conventional developing machine. Codes in the figure: 1, 1a...Casing; 2...Developing roll; 3...Photoreceptor; 4...Upper auger; 5
... lower auger; 6 ... bulkhead; 7 ... trimmer;
8... Developer; 9... Receiving portion; 10... Shooter; 11... Spiral portion; 12... Gap; 13...
Toner cartridge; 14... Dispense roll; 15... Blender; 16... Paddle wheel.

Claims (1)

[Claims] 1. A developing roll provided facing the electrostatic latent image carrier, a developing housing containing the developing roll, and a side of the developing roll facing the electrostatic latent image carrier within the developing housing. An upper auger and a lower auger are provided above and below on the opposite side.
a partition member provided in a region between the upper auger and the lower auger; the partition member includes a developer receiving portion for receiving the developer removed from the developing roll; and a partition member for receiving the removed developer. a rear chute portion that causes the developer to fall from the rear of the upper auger toward the lower auger by rotation of the upper auger, and the developer conveyed by the upper auger is delivered to the lower auger near one end in the longitudinal direction of the partition member; and a second supply port for supplying the developer transported by the lower auger to the upper auger near the other end in the longitudinal direction of the partition member. Characteristic electronic copy developing machine.